Slotted tubular members, known as slotted tubular liners or slotted metal pipes, are used in the oil industry, and in other industries, as screens to limit the amount of sand entering a well. The equipment which is used to cut these slots circumferentially around the tubular members is capable of forming slots having a width of about 0.015″ (thou=thousandths of an inch) or 0.381 mm. Slot widths less than 15 thou (0.381 mm) are needed in most industries in order to exclude sand. While equipment may be capable of cutting narrower slots, normally seaming equipment is used. Seaming equipment applies pressure to the tubular member in the vicinity of the slot to both narrow the slot width at the exterior surface of the tubular member, and to form a slot profile known as a “keystone slot.” Canadian Patent 2,183,032 issued Jul. 17, 2001 to I.S.I. Canada Inc. describes one method of reducing slot width in such tubular liners. Pressure is applied with a seaming roller to the exterior surface of a slotted pipe along the longitudinal peripheral edges of the slot until the metal pipe is deformed to close the slot to a desired width. Another scheme for reducing slot width is described in Canadian Patent No. 2,324,730 issued on Aug. 12, 2003 and reissued on Mar. 16, 2004, to Regent Technologies Ltd. This patent describes a method wherein the seaming roller traverses the slot in a helical sweep pattern in order to reduce the slot width. The apparatus described to accomplish this includes a rotating forming head equipped with three hydraulic actuators which apply a load to three forming rollers.